Bit



J. c. WRIGHT Oct. 23, 1934.

BIT

Filed Jan. 8, 1932 2 Sheets-Sheet 1 aw 0. y

Oct. 23, .1934. J c wRlGHT 1,978,006

BIT

Filed Jan. 8, 1952 2 Sheets-Sheet 2 i l /d 59 l Patented Oct. 23, 1934 v UNITED. STATES PATENT OFFICE BIT ' Jesse C. Wright, Huntington Park, Calif., assignor to Globe Oil Tools Company, Los Nietos, Calif.,

a corporation of California. v

Application January 8, 1932, Serial No. 585,469

13 Claims. (o1. 255-61) This invention relates to a well drilling tool and relates more particularly to a well bit. It is ageneral object of this invention to provide a practical and efiicient self-sharpening well drillingbit. An object of this invention is to provide a well bit involving a cutting part or blade that is stationary relative to the body of the bit and a support or backing for the blade that automatically retracts or moves upwardly as the blade Wears,so that the blade has at all times effective exposed cutting edges.

Another object of the inventionis to provide a well bit of the charactermentioned in which the backing or support for the blade while upwardly retractable is yieldingly urged downward co es to properly support the active or cutting portions of the blade.

Another object of the invention is to provide a self-sharpening bit of the character mentioned inwhich the cutting blade and the backing for the blade are replaceable.

Another object of the invention is to provide a well bit in :which a comparatively thin and therefore, sharp cutting blade of hard cutting materialmay be employed without danger of breakage or distortion.

Another object of the invention is to provide a self-sharpening well bit of the character mentioned in which the backing or supports for the cutting blade. may engage the earth or formation. at the bottom of the well bore during drill ing operations to eifectively support the cutting blade without interfering with the eflicient cutting action of the blade.

. Another object of the invention is to provide a self-sharpening well bit of the general character mentioned in which the cutting blade or blades and the backing for the blade or blades are removably attached to the shank of the bit in a positive and dependable manner by a single vide a self-sharpening bit of the character menattaching or looking member.

A further object of the invention is to pro- Fig. l is aside elevation of one embodiment of the invention showing certain parts in verticalcrossr section. Fig. 2 is a vertical detailed sectional view taken as indicated by line 2-2 on Fig. 1. Fig. 3 is a fragmentary side elevation of the tool being a view taken as indicated by line 3-3 on Fig. 1. Fig. 4 is a bottom elevation of the bit illustrated in Figs. 1, 2 and 3. Fig. 5 is a side elevation of another embodiment of the invention. Fig. 6 is a vertical sectional view taken substantially as indicated by line 6--6 on Fig. 5. Fig. 7 is a bottom elevation of the bit shown in Fig. 5. Figs. 8 and 9 are transverse detailed sectional views taken as indicated by lines 8'-8 and 9-9 on Fig. 5. Fig. 10 is a fragmentary side elevation of the bit illustrated in Fig. 5 showing the looking or holding means.

The form of the invention illustrated in Figs. 1 to 4 of the drawings, includes generally, a body or shank 10, two relatively movable elementscarried by the shank l0, namely, a cutting blade 11 and supports or backing for the blade, and means 46 for yieldingly urging one of the elements downward relative to the other.

The body or shank 10 is an elongated cylindrical member provided at its upper end with a tapered screw-threaded socket 4'7. A transverse slot 48 is provided in the lower end of the shank 10 to carryor-receive the cutting blade 11 and the backing 45. The halves or portionsof the socket 48 at opposite sides of the center of the shank are laterally offset or staggered as clearly illustrated in Fig. 4. Horizontal or transverse enlargements 49 are provided at the upper end of the slot 48. The lower Walls 50 of the enlargement 49 are inclined downwardly toward the slot 48 proper. i i

The two relatively movable elements, the cutting blade 11 and the backing 45 are carried in the slot 48 and project downwardly from the lower end of the shank l0 and laterally from opposite sides of the shank. In the embodiment of the invention being described, the cutting part or blade-11 is the relatively stationary element and the backing 45 is the movable element, and is advanced or urged downwardly by the means 46. The cutting blade 11 is a relatively thin plate of hard cutting material, and seats or bears against the forward walls of the two offset portions of the slot 48. Inpractice, the cutting blade 11 may be sectional consisting of two plates joined at the center of the blade. The side cutting edges 52 of the blade are straight and vertical, while the lower cutting edges 53 are curved and sharpened. In accordance with the broader principles of the invention, the cutting blade 11 may be attached to the shank 10' in any suitable manner. In the particular case illustrated in the drawings,

the blade 11 is welded to the lower end of the shank 10 as at 54.

The backing 45 consists of two sections 55, one section in each offset portion of the slot 48. The backing sections are slidable vertically in the slot and engage or bear against rear sides of the cutting blade sections. The backing sections 55 project from the bottom and sides of the shank 10.

In accordance with the invention, the backing 45 may be narrower than the cutting blade 11 so that the blade has exposed side cutting portions having suitable clearance. Enlarged portions or tongues 56 are provided at the upper ends of the backing sections 55 to operate or move within the slot enlargement 49. The cooperation between the enlargement 56 and the shoulder limits the downward movement of the backing relative to the shank 10.

The two backing sections are adapted to be passed or slid laterally into the two offset portions of the slot 48. A retaining ring surrounds the shank 10 to retain the backing sections 55 in the slot. After the backing sections 55 have been arranged in position in the slot 48, the ring 60 is moved to a position at an upper end of the slot and is secured to the shank 10 by screws 61. The ring 60 is provided with slots 62 registering with the upper end portions 49 of the slot 48. The slots 62 in the ring are sufficiently wide to pass the backing 55, but do not pass the tongues 56 on the backing. In this manner the ring 60 retains the movable backing 55 in position in the slot 48.

g The means 46 operates to yieldingly urge the backing 45 downwardly relative to the shank 10 and the cutting blade 11. The means 46 is in the nature of a yielding spring means for automatically advancing the backing 45 relative to the blade 11 and for allowing retraction of the backing as the blade wears. In the simple embodiment disclosed in Figs. 1 to 40f the drawings, the means 46 includes springs arranged in spaced vertical openings 66 in the shank 10. The springs 65 are arranged under compression between the upper ends of the-backing sections 45 and plugs 67 closing the upper ends of the openings 66.

The springs 65 yieldingly maintain the backing 45 in the position where it supports the cutting blade 11 against lateral or circumferential working strains. The springs are adapted to feed the backing downwardly as it wears so that the lower end of the backing is always adjacent the lower cutting end of the blade 11. The backing section 45 may be easily and quickly replaced when worn and the cutting blade may also be replaced if desired.

The embodiment of the invention illustrated in Figs. 5 to 10 inclusive of the drawings, includes, generally, a body or shank 15, cutting parts or blades 16, a support or backing block 17 for the blades 16, and means 18 urging or feeding the backing block downwardly.

The shank 15 is an elongated member adapted to be attached to the lower end of an operating string of drill pipe or the like. A tapered screw threaded socket 19 may be provided in the upper endof the shank 15 to facilitate connection of the bit with the operating string. The upper end portion of the shank 15 is of round cross sectional configuration, while the lower end portion of the shank has two downwardly inclined fiat sides 20. The lower end of the shank 15 may be flatand normal to the vertical axis of the tool. A transverse opening or slot 21 is provided in'the lower end of the shank 15 to receive or carry the blades 16 and the backing block 17. The opening or slot 21 is parallel to or extends in the same direction as the sides 20 of the shank, and is of peculiar cross section, as will be subsequently described. A central longitudinal opening 22 is provided in the shank 15 intersecting or extending upwardly from the slot 21. The upper end of the opening 22 is closed, while the lower end of the opening communicates with the slot 21.

The blades 16 are the cutting elements of the bit for cutting or acting on the formation in the well bore. The cutting parts or blades 16 are plate-like members formed of hard cutting material. In accordance with the invention, the cutting blades 16 are arranged in the opening or slot 21 and project downwardly from the lower end of the shank 15. In the construction illustrated, the cutting blades 16 are vertical and project outwardly from opposite sides of the shank 15. The side or reaming edge portions of the blades 16 extend through reduced end parts 21 of the slot 21. The walls of the reduced slot parts 21 operate to effectively support or back up the edge portions of the blades. The reaming or side cutting parts 23 of the blades 16 may be thickened and may have their rear sides bevelled or rounded as illustrated in the drawings. In the preferred construction, the cutting blades 16 project in opposite directions from the central longi tudinal axis of the shank 16 and are staggered with respect to one another as clearly illustrated in Figs. '7 and 9 of the drawings.

The invention provides novel and improved means for carrying the cutting blades 16, and for supporting the cutting blades against the upward working thrusts. A horizontal locking or holding bar 24 extends through the slot 21 and has its ends carried in a transverse opening 25 in the shank. The bar 24 is of polygonal or rectangular crosssectional configuration, and the opening 25 is'of the same shape. The upper ends of the blades 16 extend into slots 26 in the bar 24 and pins or rounded enlargements 27 on the upper ends of the blades fit a longitudinal opening 28 in the bar.

In practice, the opening 28 may be straight and continuous, and the slots 26 may be oiT-set relative to one another so asto permit the blades 16 to be staggered or oiTset. The blades 16 are assembled so that their inner edges are in abutment and thus act as a single cutting unit or blade. The upper ends 29 of the reaming portions 23 are inclined upwardly and inwardly and terminate in vertical edges 30 which extend upwardly from the upper ends of the slot portions 21. This construction locks the blades 16 in the slot or opening 21 so that they are held against lateral or outward displacement. The manner of assembling the blades 16 in the tool will be hereinafter described. The lower cutting edges 31 of the blades 16 may be straight and substantially horizontal while the cutting edges of the reaming portions 23 may be straight and vertical.

The backing block 17 is the relatively movable element of the tool and is provided to support or 4 back up the cutting blades 16. In accordance with the invention, the block 17 is a single integral member and is slidable vertically in the slot or opening 21. A vertically elongated rectangular opening 32 is provided in the block 18 to slidably pass the bar 24. The opening 32 is comparatively long vertically to permit considerable vertical movement of the backing block 17 relative to the shank 15. Vertical slots 33 extend downwardly in the block 1'? to slidably pass the cutting blades 16.

The walls of the openingor slot 21and the'exterior of the bearing block17 are flat so that the block is not liable to turn or rotate.

The backing block 17 is shaped and proportioned so that it is thicker at the rear sides ofthe blades 16 "than it is at the forward sides of the blades. As the blades 16 areat opposite sides of the axis of the tool and are offset as described above, this proportioning of the block IT'makes the block of stepped horizontal cross sectional configuration! The slot or opening 21 is correspondingly shaped to effectively slidably carry the block 17 for vertical movement. The walls of the opening or slot 21 may be relievedor provided with recesses 34toreduce the frictional engage- The backingblock 17 projects below the lower. end of the shank 15 to back up and support the projecting cutting portions against the cutting thrusts of theblades 16. Thethicker portions of the block 17 at the rear sides of the blades 16 may project downwardly from the lower end of the shank a greater distance than the thinner portions of the block. The lower'ends of the projecting portions of the block 17 are preferably roundedsothat the block 17 will not bite or cut into the formation during operation of the tool.

The means 18 forurgingthe backing block 1'7 downwardly is in the nature of a spring means. A helical spring 36 is arranged in the opening 22 to yieldinglyhold the block 17 in a down position.

The spring 36 is arrangedunder compression 'between the upper end of the block 17 and the upper end of the'opening 22.

A stem 37 may be provided on the upper end ofthe block 17 to center and guide the spring 36. The opening 22 may contain grease or other suitable lubricant for lubricating the block 17. The spring 36 nor,- mally yieldingly urges the block 17 downwardly so that the blockis maintained in a position opening 25 in a manner so that the opening 28 receives the pins 27 and the slots 26 receive the blades 16. One of the. slots 26 is formed sufficiently wide to pass both of the staggered blades 1 16 as clearly illustrated in Figs. 6 and 10 of the drawings. After the lock bar 25 has been arranged in the manner just described, its ends may be welded to the shank 15 around the opposite ends of the opening 25. The invention includes means for flushing the cutting blades 16 with circulation fluid. Branch circulation. passages 38 extend downwardly from the socket l9 and have their lower ends open at the side walls of the opening or slot 21. Fluid discharge pasi sages 39 are provided in the backing block 17.

The upper ends of the discharge passages 29 are opposite or register with the lower ends of the passages 38. The circulation fluid is discharged downwardly from thelower ends of the passages 39 and against the sides of the blades 17. The

opposing ends of the passages 38 and 39 are sufficiently long to remain in register throughout the entire range of movement of the backing block 17.

- It is believed that the operation of the tool illustrated in Figs. to of the drawings will be readily understood from the fore-going detailed description. The cutting blades 16 project down- Wardly and outwardly from the shank to have effective cutting engagement with the formation. The blades 16 are supported against the upward working thrusts by the lock bar 24, while the pins 27 prevent downward movement of the cutting blades. The spring 36 maintains the backing block 17 in a position where it effectively backs up or braces the blades 16. The walls of the slots 33 have long bearing orsupporting engagement with the opposite sides of the blades 16 so that the blades are supported by the block 21 the major portions of their lengths. The lower end of the block'17 is always in bearing engagement or supporting engagement with the cutting blades adjacent the active cutting edge portions of the blade. As the backing block .17 is yieldingly urged downwardly, its engagement with the formation at the bottom of the well bore does not in any way interfere with the free and effective cutting action of the blades 16. As the blades 16 become shortened through wear, the block 17 retracts upwardly into the slot or opening 21 and does no-t become appreciably worn, and does not interfere with the cutting action of the blades 16. It is to be particularly noted that the lock bar 24 operates to support or carry the cutting blade 16 and to limit longitudinal movement of the block 17 in both directions. Further, the bar 24 aids in guiding the block 17 for vertical movement. The lubricant carried inthe opening 22 provides for the free and smooth movementof the block 17 and prevents the accumulation of solid matter in the interior of the tool.

The present invention provides a well drilling bit in which a comparatively long and therefore long wearing cutting part is effectively backed up or supported against the working thrusts during operation so that it is not liable to breakage or distortion. The cutting part may be simple and inexpensive of manufacture and may be readily replaced. As the backing or support for the cutting blade is yieldingly held in its position it does not interfere with the proper cutting action of the blade and is not appreciably worn.

Having described only typical forms and applications of my invention, I do not wish to limit myself to the specific detailsset forth, but wish to reserve to myself any. changes or variations that may appear to those skilled in the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. A well bit including a shank having a slot in its lower end, a cutting blade projecting from the shank, a retractable member backing up the blade and slidable in the slot, and means removably retaining the member in the slot, said means including a detachable ring surrounding the shank and closing the opposite ends of the slot.

2. A well bit including a shank having a slot in its lower end, a cutting blade projecting from the shank, a retractable member backing up the blade and slidable in the slot, and means removably retaining the members in the slot, said means including a bar carried by the shank and ex tending through the slot and an opening in sai member.

3. A well bit including a shank having an opening, a cutting blade extending into the opening and projecting from the lower end of the'shank, a bar extending through the opening and carrying the blade, a block slidable vertically in the opening and having an opening passing the bar, and means urging the block downwardly to back up the projecting part of the blade.

4. A well bit including a shank having an opening, a cutting blade extending into the opening and projecting from the lower end of the shank, a bar extending through the opening and carrying the blade, a block slidable vertically in the opening and having an opening passing the bar, and means urging the block downwardly to back up the projecting part of the blade, said means including a spring in the opening.

5. A well bit including a body having an opening, a cutting blade projecting from the body and having one side bearing against a wall of the opening, means attaching the blade to the body, and means independent of said means for bracing the blade including a member shiftable in the opening and having bearing engagement with the opposite side of the blade, and means urging the member outward on the blade to be in engagement with said opposite side of the projecting part of the blade and yieldable to permit retraction of the member through its engagement with the earth formation as the blade wears.

6. A well bit including a shank having an opening, a cutting blade projecting from the lower end of the shank at opposite sides of the axis of rotation of the shank, the blade beingpositioned to have the forward side of its projecting portion i flushed by the fluid discharging from the passage, means attaching the blade to the shank, members independent of said means in sliding bearing engagement with the walls of the opening and projecting from the shank to be in supporting engagement with the rear sides of the projecting blade relative to the direction of rotation of the bit at the opposite sides of the axis of the shank, and means urging the members outward on the blade and yieldable to permit automatic retraction of the members through engagement with the bottom of the bore as the blade wears.

7. A well bit including a shank having a slot, a cutting blade, and means attaching the blade j to the shank to project therefrom, the bit being characterized by a blade bracing member having parallel front and rear sides and slidable in the slot to have its rear side bear on a wall of the slot, the member being adapted to project from 1 the body to have its front side in bracing or bearing engagement with the projecting portion of the blade, and means independent of the attaching means holding the member in a position where it projects from the shank to engage the projecting portion of the blade, the last mentioned means being yieldable to permit automatic retraction of the member as the blade wears. 1

8. A well bit including a shank having an opening, a cutting blade projecting from the Q shank, means rigidly attaching the blade to the shank, a member independent of said means and having sliding bearing engagement with the wall of the opening and with the rear side of the blade, and means urging the member outwardly to have supporting engagement with the rear side of the projecting cutting portion of the blade. the last mentioned means being yieldable to permit retraction of the member inwardly in the opening through engagement with the earth formation as the blade wears.

9. A well bit including a shank having a slot, a cutting blade projecting from the shank, means attaching the blade to the shank, a backing member independent of said means and having parallel front and rear sides, the front side being in sliding bearing engagement with a wall of the slot, and means yieldingly holding the member in a position where it projects from the shank to have its front side bear against and back up the outer edge portion of the blade, the last mentioned means including a spring reacting between the shank and the member yieldable to permit retraction of the member caused by its engagement with the formation as the blade wears.

10. A well bit including a shank having an opening, a cutting blade projecting from the lower end of the shank, means attaching the blade to the shank, and an upwardly retractable backing member independent of said means slidably bearing in the opening and projecting from the shank to engage opposite sides of the projecting portion of the blade, the member being retractable as the blade wears.

11. A' well bit including a shank, a cutting blade projecting from the lower end of the shank and having a substantially flat rear side, means attaching the blade to the shank, and an upwardly retractable backing member independent of the said means and normally in backing up engagement with the rear side of the projecting portion of the blade, the member being retractable as the blade wears and remaining in backing up cooperation'with' the blade during such retraction.

12. A well bit including a shank, a cutting blade projecting from the lower end of the shank and having substantially fiat opposite sides, means attaching the blade to the shank, and an upwardly retractable blade bracing member independent of said means and normally in backing up engagement with the said opposite sides of the projecting portion of the blade, the member being retractable as the blade wears.

13. A well bit including a shank having a slot in its lower end, a cutting blade projecting from the shank, means attaching the blade to the shank, a retractable member independent of the said means slidable in the slot and projecting from the shank to be in supporting engagement with the projecting cutting portion of the blade, the member being automatically retractable as the bit wears and remaining in supporting engagement with the blade during such retraction, and means removably retaining the member in the slot.

JESSE C. WRIGHT. 

